The House Oversight Committee formally demanded answers from four federal agencies Monday on the deaths and disappearances of at least 11 American scientists and researchers with ties to NASA, nuclear research, and classified defense programs—several of them directly connected to the space defense technologies now being commercialized by SpaceX and Blue Origin.

Committee Chairman James Comer (R-Ky.) and Rep. Eric Burlison (R-Mo.), the chair of the Subcommittee on Economic Growth, Energy Policy, and Regulatory Affairs, sent letters to FBI Director Kash Patel, Secretary of Energy Chris Wright, Secretary of Defense Pete Hegseth, and NASA Administrator Jared Isaacman, requesting staff-level briefings no later than April 27.

“If the reports are accurate, these deaths and disappearances may represent a grave threat to U.S. national security and to U.S. personnel with access to scientific secrets,” the letters read.

Later on Monday, Comer said the string of deaths was unlikely to be a coincidence. “Once you see the facts, it would suggest that something sinister could be happening and it would be a national security concern,” Comer said, adding he and Burlison were looking to “see if we can put it together and find any missing links to try to solve what’s going on here. Because it’s very unlikely that this is a coincidence. Congress is very concerned about this. Our committee is making this one of our priorities now because we view this as a national security threat.”

White House responds

The White House formally acknowledged the pattern on April 15, when press secretary Karoline Leavitt was asked directly about it at a briefing. “If true, of course, that’s definitely something I think this government and administration would deem worth looking into,” she responded.

Later that day, President Trump told reporters, “I don’t know. Hopefully, coincidence, whatever you want to call it. But some of them were very important people,” adding he would have answers within “the next week and a half.” 

“I just left a meeting on that subject, so pretty serious stuff.”

In a post on X two days later, Leavitt confirmed the administration “is actively working with all relevant agencies and the FBI to holistically review all of the cases together and identify any potential commonalities that may exist,” adding, “No stone will be unturned.” 

On Sunday, Patel confirmed the FBI is formally investigating. “We’re going to look for connections,” he told Fox News, “on whether there are connections to classified access, access to classified information, and or foreign actors.”

“If there’s any connections that lead to nefarious conduct or conspiracy, this FBI will make the appropriate arrest.”

The bureau told Fortune in a statement, “The FBI is spearheading the effort to look for connections into the missing and deceased scientists. We are working with the Department of Energy, Department of War, and with our state and local law enforcement partners to find answers.”

When asked for comment, NASA directed Fortune to its first official statement on the matter in an X post. “NASA is coordinating and cooperating with the relevant agencies in relation to the missing scientists. At this time, nothing related to NASA indicates a national security threat. The agency is committed to transparency and will provide more information as able.”

SpaceX and Blue Origin, and the scientists involved

The committee’s letters focus on NASA and nuclear research connections, but the broader context is the commercial space-defense industry that these scientists helped build. The planetary defense and nuclear research fields are notably insular: There are only a couple hundred scientists who specialize in asteroid characterization, deflection modeling, and space-based detection.

Blue Origin unveiled its NEO Hunter planetary defense concept in March 2026, developed in partnership with California’s Jet Propulsion Laboratory (JPL) and Caltech and built on its Blue Ring spacecraft platform. The ion-beam deflection and kinetic impact capabilities it proposes share core technology with missile-defense detection and interception systems. 

Both companies have received substantial federal contracts under the Trump administration. Space Force awarded SpaceX nearly $6 billion and Blue Origin approximately $2.3 billion in national security launch contracts in April 2025. SpaceX is separately under contract for the Golden Dome missile defense satellite constellation; Blue Origin has been added to the $151 billion SHIELD contract through the Missile Defense Agency and hired its first-ever president of national security in December 2025. 

NASA Administrator Isaacman, one of the four letter recipients, has championed the expansion of the privatization of missions previously managed by government agencies. Neither SpaceX nor Blue Origin responded to Fortune’s requests for comment.

The letters flag a close professional tie between two of the missing: Aerojet Rocketdyne and JPL engineer Monica Reza and retired Air Force Maj. Gen. William Neil McCasland, both of whom vanished, in 2025 and 2026 respectively. The letters note that the two worked together on “an Air Force–funded research program in the early 2000s pertaining to advanced materials needed for reusable space vehicles and weapons,” which Comer and Burlison say has not been explained.

Deaths and disappearances

The cases date back to 2022 and span JPL, Los Alamos National Laboratory, MIT, Caltech, and the Kansas City National Security Campus. Reza, 60, was director of JPL’s materials processing group and had patented a nickel super-alloy used in both space travel and weaponry when she vanished during a hike on Angeles Crest Highway in June 2025 and was never found. She patented a nickel super-alloy for rocket manufacturing, research that went into reusable rocket programs like New Glenn and Starship. McCasland, 68, disappeared from his Albuquerque home on Feb. 27 of this year, leaving on foot with only a .38 caliber revolver.

JPL principal scientist Frank Maiwald, 61, died on July 4, 2024, with no cause of death released and no statement from NASA. Government contractor Steven Garcia, who oversaw nuclear weapons assets at the Kansas City National Security Campus, disappeared from Albuquerque in August 2025, last seen on surveillance footage leaving on foot with a handgun.

Michael Hicks, who worked at JPL from 1998 to 2022, passed away in July 2023 at age 59. He worked on asteroid characterization research that was used in NASA’s Double Asteroid Redirection Test (DART) mission, and was the same methodology that Blue Origin’s NEO Hunter was modeled on and SpaceX’s Falcon 9 originally launched in 2021. Caltech astrophysicist Carl Grillmair was found shot dead on his front porch in rural Llano, Calif., earlier this year. The 67-year-old worked on NEOWISE and NEO Surveyor telescopes that are the detection backbone used by NEO Hunter. SpaceX is contracted to carry NEO Surveyor to orbit on a Falcon 9 in 2027.

Two Los Alamos National Laboratory employees, Anthony Chavez and Melissa Casias, vanished weeks apart in 2025 under nearly identical circumstances, each leaving behind their car, keys, wallet, and phone. Jason Thomas, an assistant director at Novartis with active DOD contracts, disappeared in December 2025 and was found dead in a Massachusetts lake three months later.

A former colleague of one of the deceased spoke to Newsweek, describing the concentration of deaths and disappearances within such a small, specialized field as defying ordinary probability. Joe Masiero, a lead scientist at the California Institute of Technology, told the publication: “It’s really unfortunate to see a tragedy played out over and over again.”

Former FBI official Chris Swecker recently shared that the pattern is consistent with how “several foreign powers” operate, by “abducting, blackmailing, torturing, and even killing” scientists to gain intel.